It is austerity-ridden, black-market-riddled, post-war England and MI5 has pushed Cockney cat burglar and jewel thief Jethro out onto the rooftops of London again in defence of The Realm. And if that was not bad enough, London's top villains want him to do a bit of burglary for them too. Ever looming in the background are the twin spectres of the growing communist menace and a resurgence of fascism. There are even rumours that an American OSS agent is roaming around London with his eagle eye set on someone who looks an awful lot like Jethro. Things turn decidedly deadly when Jethro stumbles across a Royal cover-up and an extreme right-wing plot to topple Britain's new Labour Government. And all this is a mere precursor to Jethro having to pull off a very dodgy and dangerous caper, the success or failure of which could save England from going to the dogs or spell curtains for Jethro.